Comparison of ethylenediaminetetraacetic acid and sodium citrate as anticoagulants in collection of samples for cytomegalovirus pp65 antigen detection in renal transplant recipients with suspected cytomegalovirus disease

Cytomegalovirus (CMV) is a major cause of morbidity and mortality in immunocompromised patients. Antigenemia and polymerase chain reaction (PCR) assay are used for diagnosis of CMV disease. A number of anticoagulants are used for the collection of blood samples for antigenemia assay. Thus, ethylenediaminetetraacetic acid (EDTA) and sodium citrate are evaluated for the collection of blood samples and their effects on antigenemia and PCR. Twenty renal transplant recipients with clinically suspected CMV disease and 10 healthy individuals were included in the study. Peripheral blood mononuclear cells (PBMCs) extracted from blood samples were subjected for antigenemia and PCR assay. In 15 out of 20 patients, the number of peripheral blood mononuclear cells obtained were higher in EDTA anticoagulated samples than in sodium citrate. CMV pp65 antigenemia was detected in 10 EDTA and 9 sodium citrate samples, respectively. Number of antigen positive cells in EDTA samples were significantly higher than that of sodium citrate (P<0.05). None of the anticoagulants had adverse effect on the detection of CMV DNA. Thus, EDTA was found to be a better anticoagulant for separation of PBMCs and thus, for CMV pp65 antigenemia assay than sodium citrate.